The present invention relates to a method for forming an oblique projection original such as a film which may be obliquely projected onto a screen with the projected image thereof equivalent to a corresponding orthogonal projection image, and to an apparatus for forming the oblique projection original.
An overhead projector (OHP) or a slide projector is known as an apparatus which applies light to a film original on which characters or pictures are provided to project the image thereof onto a screen. In order that the image of a film loaded in the projection apparatus may be orthogonally projected onto the screen, it is necessary that the surface of the film in the projection apparatus be parallel to the screen. However, as the operator or observer is positioned behind the projection apparatus, it is sometimes rather difficult to observe the image on the screen.
Accordingly, an object of this invention is to eliminate the above-described difficulty accompanying a conventional projection original. More specifically, an object of the invention is to provide a method for forming an oblique projecting original which may be obliquely projected on the screen, that is, with the screen inclined with respect to the original, and the resultant image on the screen is equivalent to an orthogonally projected image.